Microsoft this Friday will ship the final pre-release version of Windows Vista and, unexpectedly, will name the release as Release Candidate 2 (RC2). Previously, Microsoft had publicly asserted that it would not ship an RC2 milestone release of Windows Vista. But don't let the name fool you: RC2 is really just a standard interim build of Vista and will not be given out to millions of users as was RC1.

The RC2 build is 5743, and Microsoft is currently testing it internally. As with the previous interim build, 5728, RC2 will be given out to beta testers, MSDN and TechNet subscribers, and a random, limited selection of Consumer Preview Program (CPP) members.
While Microsoft wouldn't confirm the specifics of the release, the company did corroborate that it was planning an upcoming interim Vista build. "As we have previously discussed, Microsoft does plan to deliver one more interim build of Windows Vista before releasing the final product," a Microsoft spokesperson told me. "The exact name of the build, and the date of its release, have not been announced."

This is the last build Microsoft will be making available to the public prior to RTM, or "release to manufacturing." That date--which was previously referred to as "on or before October 25"--has been adjusted slightly. Now, the Vista "launch window" begins October 18, when Microsoft will begin testing the final planned build for RTM. But Microsoft doesn't expect to finalize the product until sometime between October 25 and November 8.

Internal documentation notes that each daily delay after October 25 comes at a price, however: For each day past October 25, Microsoft will start to lose languages for the January launch. However, the company is prepared to do that to ensure that Vista's quality is high.

That documentation also notes that there are over 1400 open bugs in Vista at this time. Microsoft's internal processes require this bug count to drop to 500 or fewer before they will attempt to go into escrow for RTM. By comparison, there were over 2479 bugs on September 22.